Free Hot Water Unit Secures Industry Recognition

Mitsubishi Electric’s innovative PWFY City Multi water heater secured industry recognition at the prestigious RAC Cooling Industry Awards recently, winning the category for Environment Pioneer – Air Conditioning Product of the Year.

The PWFY water heater uses advanced heat pump technology to transfer excess heat from a VRF (Variable Refrigerant Flow) system to offer buildings a constant supply of hot water. The new unit comes in two versions which deliver water temperatures of either 70ºC or 45ºC and builds on the groundwork of Mitsubishi Electric’s successful PQFY system launched two years ago.

“This effectively offers building owners the chance to heat water virtually for free by using excess heat from their air conditioning system and we are delighted that the judges have recognised the potential carbon and fuel cost savings that the PWFY can offer,” said an ecstatic Philip Ord, Air Conditioning Product Marketing Manager for the Hatfield-based company. Philip collected the Award at the black tie event at the Hilton on London’s Park Lane.

“This is the first of its type in the air conditioning industry and is another example of how we can capitalise on the heat recovery potential of VRF systems to provide incredible energy efficiency within a building’s services,” added Ord.

The heat pump boiler uses a cascade refrigeration cycle to raise the water temperature, instead of simply discharging any excess heat from the refrigerant to the air as in a conventional split type air conditioner. “This effectively provides free hot water and is far more fuel efficient than other systems, helping to reduce running costs,” added Ord. “It is also around four times better than the most efficient type of conventional gas boiler on a kW / kW basis, leading to a substantial reduction in CO2 emissions.”

The PWFY allows building owners to get rid of their commercial gas and oil boilers as it can even work with off-the-shelf water cylinders to provide customers with added functionality, ease and convenience.

Figures from Defra’s Market Transformation Programme (2006) show that the provision of heating and hot water accounts for over 50% of the energy consumed by non-domestic buildings. Initial modelling from the Defra study of gas and oil-fired water heating boilers and warm air and radiant systems showed annual carbon emissions of 10.8 MtC.

The model also shows that there is a link between gas boiler efficiency and age ranging from 50% efficiency for a pre-1979 gas boiler, to 81% for boilers from 2007 onward. Providing hot water through the heat recovery process of heat pumps can offer average efficiency levels of 400% in comparison.

“It is difficult to find accurate figures of the size of the commercial boiler market but even if the general inefficiencies, generation and transmission losses of the national grid are taken into account, it is obvious that a system with a performance of 400% plus will give you a better carbon reduction performance and a more efficient delivery system than one working at 81%,” explained Ord.

“If all VRF air conditioning systems were optimised in this way, we could completely replace the need for carbon-based water heating systems. Just think what that could do for the energy efficiency levels of the country – and the energy bills of hard pressed businesses!”